Urology Annals

: 2012  |  Volume : 4  |  Issue : 3  |  Page : 195-

Urinary pH, melamine, and kidney stone formation

Somsri Wiwanitkit, Viroj Wiwanitkit 
 Wiwanitkit House, Bangkhae, Bangkok, Thailand

Correspondence Address:
Somsri Wiwanitkit
Wiwanitkit House, Bangkhae, Bangkok, Thailand 10160

How to cite this article:
Wiwanitkit S, Wiwanitkit V. Urinary pH, melamine, and kidney stone formation.Urol Ann 2012;4:195-195

How to cite this URL:
Wiwanitkit S, Wiwanitkit V. Urinary pH, melamine, and kidney stone formation. Urol Ann [serial online] 2012 [cited 2020 May 25 ];4:195-195
Available from: http://www.urologyannals.com/text.asp?2012/4/3/195/102678

Full Text


A recent publication on urinary pH, melamine, and kidney stone formation is very interesting. [1] Lu et al. reported "an association of gender and urinary pH with melamine-associated kidney stone formation risk". [1] This can be useful epidemiological information. However, some facts of medical biochemistry should be discussed. The reported pH in this publication is not clear. Only a value of < and ≥6.5 can be read. Indeed, the correlation can be directly assessed by the correlation study between the exact urine pH value and solubility. Based on chemical structure, melamine is a base and increases solubility in acidic conditions (very good if pH is lower than 4). [2] However, it is a fact that the range of human urine pH is not wide (4.5-8); hence, the solubility of melamine might be affected slightly.


1Lu X, Wang J, Cao X, Li M, Xiao C, Yasui T, et al. Gender and urinary pH affect melamine-associated kidney stone formation risk. Urol Ann 2011;3:71-4.
2WHO. Background Paper on the Chemistry of Melamine Alone and in Combination with Related Compounds. Available online at www.who.int/entity/foodsafety/fs_management/Melamine_2.pdf.